Method of surgical dissection and/or guidance of other medical devices into body

ABSTRACT

A method of surgical dissection of tissue with a dissector comprising: an elongate shaft comprising a proximal portion and a distal portion, wherein the distal portion comprises a plurality of segments that articulate with respect to one another and the plurality of segments includes a distal segment having a distal end; and a handle attached to the proximal portion of the shaft, wherein the handle comprises controls for articulating the plurality of segments of the distal portion of the shaft with respect to one another, comprising the steps of: positioning the distal end of the dissector in a body; advancing the distal end through the body to dissect tissue; and simultaneously articulating the plurality of segments with respect to one another. A method of surgical dissection of tissue and guiding a second device to a desired physiological location with a first device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Patent Application havingSer. No. 11/698,764, filed Jan. 26, 2007, which claims the benefit ofboth U.S. Provisional Application having Ser. No. 60/762,683, filed Jan.27, 2006, entitled “MEDICAL DEVICE,” and U.S. Provisional Applicationhaving Ser. No. 60/852,145, filed Oct. 17, 2006, entitled “MEDICALDEVICE,” which applications are incorporated herein by reference intheir entireties.

This application also incorporates by reference in its entiretyco-pending U.S. Patent Application having Ser. No. 11/698,807, filed onJan. 26, 2007, entitled “DEVICE AND SYSTEM FOR SURGICAL DISSECTIONAND/OR GUIDANCE OF OTHER MEDICAL DEVICES INTO BODY”.

FIELD OF THE INVENTION

The present invention relates generally to a medical device and methodfor surgical dissection and/or guidance of other medical devices into abody and, in particular, a medical device and method for both dissectingcardiac tissue prior to positioning an ablation device, and guiding theablation device into a beating heart to perform lesions on the heartduring a minimally invasive procedure.

BACKGROUND OF THE INVENTION

Various specialized medical devices, such as ablation devices, cardiacleads, ultrasonic catheters, balloon angioplasty catheters,electrophysiological diagnostic catheters, pressure monitoringcatheters, etc., may require the use of a delivery system for deployingthe device in a desired internal body space, such as the heart, forexample. In addition, in some cases, dissection of tissue is desired ornecessary to guide or deliver such specialized medical devices to adesired location.

Although the present invention contemplates devices and systems fordissecting tissue and/or guiding other specialized medical devices tomany areas of the body, in particular, the present application willfocus on one exemplary desired location and one exemplary specializedmedical device. The focus will be primarily on delivery of an ablationdevice to an area on or near the heart, which, in particular, is aroundthe two separate pairs of pulmonary veins on both sides of the heart.Similarly, the present invention contemplates the use of the presentinventive devices and systems to treat various conditions. However, inparticular, the present application will focus on treatment for heartarrhythmias (e.g., atrial fibrillation) using ablation procedures.

In a normal heart, contraction and relaxation of the heart muscle(myocardium) takes place in an organized fashion as electrochemicalsignals pass sequentially through the myocardium from the sinoatrial(SA) node located in the right atrium to the atrialventricular (AV) nodeand then along a well-defined route which includes the His-Purkinjesystem into the left and right ventricles. Sometimes abnormal rhythmsoccur in the atrium which are referred to as atrial arrhythmia. Three ofthe most common arrhythmias are ectopic atrial tachycardia, atrialfibrillation, and atrial flutter. Arrhythmia can result in significantpatient discomfort and even death because of a number of associatedproblems, including the following: (1) an irregular heart rate, whichcauses a patient discomfort and anxiety; (2) loss of synchronousatrioventricular contractions, which compromises cardiac hemodynamicsresulting in varying levels of congestive heart failure; and (3) stasisof blood flow, which increases vulnerability to thromboembolism. It issometimes difficult to isolate a specific pathological cause of thearrhythmia, although it is believed that the principal mechanism is oneor a multitude of stray circuits within the left and/or right atrium.These circuits or stray electrical signals are believed to interferewith the normal electrochemical signals passing from the SA node to theAV node and into the ventricles.

Treatment of arrhythmias may be accomplished by a variety of approaches,including drugs, surgery, implantable pacemakers/defibrillators, andcatheter ablation. While arrhythmic drugs may be the treatment of choicefor many patients, these drugs may only mask the symptoms and do notcure the underlying cause. Implantable devices, on the other hand,usually can correct an arrhythmia only after it occurs. Surgical andcatheter-based treatments, by contrast, may actually cure the problemusually by ablating the abnormal arrhythmogenic tissue or abnormalpathway responsible for the arrhythmia. The catheter-based treatmentsrely on the application of various destructive energy sources to thetarget tissue including direct current energy sources to the targettissue, including direct current electrical energy, radiofrequencyelectrical energy, microwave energy, laser energy, cryoenergy,ultrasound, and the like.

One surgical method of treating arrhythmia is the “Maze” procedure,which relies on a prescribed pattern of incisions to anatomically createa convoluted path, or maze, for electrical propagation within the leftand right atria. The procedure employs incisions in the right and leftatria, which divide the atria into electrically isolated portions, andwhich in turn results in an orderly passage of a depolarization wavefront from the SA node to the AV node, while preventing reentrant wavefront propagation. The Maze procedure has been effective in curingarrhythmias, but the procedure is technically difficult. The procedurealso requires open heart surgery, in which the breastbone is divided andthe surgeon has direct access to the heart.

More recently, Maze-like procedures have been developed utilizingablation catheters that can form lesions on the endocardium toeffectively create a maze for electrical conduction in a predeterminedpath. Typically, the lesions are formed by ablating tissue with anelectrode carried by a catheter. Ablative energy, e.g., high intensityfocused ultrasound (HIFU) energy, radiofrequency (RF) energy, microwaveenergy and/or laser energy, applied to the electrode, causes significantphysiological effects in the tissue resulting from thermal and/ormechanical changes or effects. By controlling the energy level, theamount of heat generated in the tissue and the degree of tissue damageor change can also be controlled. Ablation uses lower levels of voltagethat creates sufficient heat to cause a desired cell damage, but leavesthe tissue structure intact so as to effectively block electricalpathways within the tissue. Irrigation of the electrode(s) with salineor other conductive fluid can decrease the interface impedance, cool thetissue, and allow for a greater lesion depth.

A treatment for atrial fibrillation, in particular, includes ablationaround the pulmonary veins, which procedure is called pulmonary veinantrum isolation. Almost all the atrial fibrillation signals arebelieved to come from the four pulmonary veins and move to the atria.Ablation of the area of the atria that connects to the pulmonary veinsprovides circular scar tissue that blocks impulses firing within thepulmonary veins from moving to the atria, thereby disconnecting thepathway of abnormal rhythm and preventing atrial fibrillation.

Most ablation devices are designed to access the heart via a mid-linesternotomy. More recently, ablation of cardiac tissue can be carried outthrough a minimally invasive route, such as between the ribs, through asub-xyphoid incision or via catheter that is introduced through a vein,and into the heart. Such minimally invasive procedures are generallyperformed off-pump, which means the heart is beating during theprocedure. Such procedures accordingly require several ports for medicaldevices to enter the area of the heart and perform the procedures.

Ablation of a precise location within the heart requires preciseplacement of an ablation device within or near the heart. Precisepositioning of the ablation device is especially difficult because ofthe physiology of the heart, particularly as such recently developedprocedures generally occur off-pump. As discussed earlier, in somecases, dissection of tissue is necessary to guide or deliver specializedmedical devices to their desired location in the body. In particular,with regard to pulmonary vein antrum isolation, tissue connecting eachpair of pulmonary veins to pericardial reflections is often dissectedallowing ablation device placement on and/or around the pulmonary veins.

In general, if prior art devices for dissection are used, and ifguidance of a specialized medical device to a location after thedissection is desired, separate devices are used for dissection and forplacing the specialized medical device. Prior art devices that allow forboth dissection and placement of another device, in particular withregard to ablation devices, require suturing a catheter at or near theend of the device while the end of the device is near the heart.Suturing near a beating heart involves risk of negative consequences.

Thus, there is a need for an improved device that can dissect tissue andguide specialized medical devices to particular locations in the body.In particular, an improved device and method for dissecting cardiactissue and placement of ablation devices during minimally invasiveprocedures on a beating heart are desired.

SUMMARY OF THE INVENTION

The present invention relates to dissection of soft tissue duringgeneral, ear, nose and throat (ENT), thoracic, urological, andgynecological surgical procedures. The present invention is ofparticular applicability for use during minimally invasive surgicalprocedures or endoscopic procedures, such as during procedures on abeating heart involving ablation (e.g., pulmonary vein antrumisolation). The device includes a shaft with an articulating end that isadjusted by controls in a handle. The articulated end helps to navigatesoft tissue around anatomic structures. The articulating end preferablycomprises a plurality of moveable or articulable segments that help todissect tissue and move around anatomic structures. Preferably, thearticulated end is also illuminated for identification of distal tiplocation.

The device may be part of a system used to dissect tissue and/or guide aspecialized medical device to a location in the body. The device may beinserted into a location in the body, as described above, via a givenentry route, for dissection of tissue. While the device is in thelocation in the body for dissection purposes, the device may also beused with other components of a system to place a second device in thebody. In order to place the second device, the system preferablyincludes a guide wire that may be fed through a lumen in the device andthat may be advanced through the device and connected to one end of aguide member, which has two ends, and that is separate from the device.The guide wire may then be retracted back through the device, with theguide member attached, in order to pull the first end of the guidemember to a location in the body, and preferably adjacent or near thedistal tip of the device. The second end of the guide member may beattached to a second device, such as a specialized medical device (e.g.,an ablation device). The device, with guide member attached, may then beremoved from the body by withdrawing the device back through the port ofentry, thereby pulling the guide member through the same port, andfurthermore pulling the second device on the second end of the guidemember into the location in the body at or near where the dissectiontook place.

The present invention provides advantages over prior art devices andmethods for dissection of tissue and/or guidance of medical devices intoa body. One advantage is that a plurality of articulable segments of adistal end of the device can have different configurations allowing theend of the device to have, for example, a straight configuration forinsertion and removal through a port during a minimally invasivesurgical procedure and also allowing the end of the device to articulateinto controlled curves while inside the body for dissection andplacement purposes. Another advantage is that a portion of the devicecan remain outside of the body so as to indicate both a plane ofarticulation and an amount of articulation of the articulating end ofthe device for informing the user of such relevant information. Yetanother advantage of the present invention is the presence of an on-offswitch for an illumination source on the distal end of the device, whichallows the user to control whether or not an illumination source isturned on. Also, an illumination source indicator is preferably locatedon the handle, which provides the advantage of allowing the user to knowwhether or not the illumination source is turned on. A still furtheradvantage is that a guide wire may be used, through a lumen in thedevice, such as in the case of an ablation procedure in particular, toplace a device, which avoids suturing inside the body (e.g., near thebeating heart in ablation procedures). Also, with regard to ablationprocedures in particular, an additional advantage is that thevariability of the articulation of the articulating end of the deviceallows a surgeon some flexibility in the type of surgical approachchosen for a given procedure and patient. For example, in pulmonaryantrum isolation procedures, a surgeon may choose to use either asuperior or an inferior approach to the procedure using the deviceand/or system of the present invention.

A first embodiment of the present invention is a method of surgicaldissection of tissue with a dissector comprising: an elongate shaftcomprising a proximal portion and a distal portion, wherein the distalportion comprises a plurality of segments that articulate with respectto one another and the plurality of segments includes a distal segmenthaving a distal end; and a handle attached to the proximal portion ofthe shaft, wherein the handle comprises controls for articulating theplurality of segments of the distal portion of the shaft with respect toone another, comprising the steps of: positioning the distal end of thedissector in a body; advancing the distal end through the body todissect tissue; and simultaneously articulating the plurality ofsegments with respect to one another. The distal end may include anillumination source, and the method may further comprise a step ofvisually locating the distal end of the elongate shaft by observingvisible energy from the illumination source passing through tissue. Thedistal end may include an illumination source, and the method mayfurther comprise a step of differentiating tissue by observing visibleenergy from the illumination source through tissue.

A second embodiment of the present invention is a method of guiding asecond device to a desired physiological location with a first devicecomprising: an elongate shaft comprising a proximal portion and a distalportion, wherein the distal portion comprises a plurality of segmentsthat articulate with respect to one another and the plurality ofsegments includes a distal segment having a distal end; a handleattached to the proximal portion of the shaft, wherein the handlecomprises controls for articulating the plurality of segments of thedistal portion of the shaft with respect to one another; and a guidewire lumen having a proximal and a distal end, wherein the guide wirelumen is disposed along at least a portion of the length of the firstdevice and the guide wire lumen has openings at both the proximal anddistal ends, comprising the steps of: inserting the first device, distalend first, into a first opening in a body with the plurality of segmentsof the distal portion in a substantially straight configuration;advancing the distal portion through the body; articulating theplurality of segments with respect to one another to position the distalportion in a desired physiological location; feeding a guide wire,having a proximal and a distal end, into the proximal opening of theguide wire lumen, distal end first, and through the guide wire lumenuntil the distal end of the guide wire comes out the distal opening ofthe guide wire lumen in the distal end of the first device; connectingthe second device to the distal end of the guide wire; and pulling theguide wire back through the first device and thereby pulling the seconddevice adjacent the distal end of the first device at or near a desiredphysiological location. The method may further comprise the step of:removing the first device through the first opening. Prior to the stepof removing the first device, the distal portion of the first device maybe returned to the substantially straight configuration. The method mayfurther comprise the steps of: disconnecting the second device from theguide wire; and removing the first device and the guide wire through thefirst opening. The second device may have been inserted into the bodythrough a second opening in the body before connecting the second deviceto the guide wire. The distal end may include an illumination source,and the method may further comprise the step of visually locating thedistal end of by observing visible energy from the illumination sourcepassing through tissue. The illumination source may be turned off andon. The first device may further comprise an articulation lock mechanismfor maintaining the distal portion of the device in a desiredarticulated configuration, and further comprising the step of lockingthe distal portion in the articulated position while the distal portionis in the desired physiological location. The first device may furthercomprise an articulation lock mechanism for maintaining the distalportion of the device in a desired articulated configuration, andfurther comprising the steps of: locking the distal portion in thearticulated position while the distal portion is in the desiredphysiological location; and unlocking the distal portion prior toreturning the distal portion of the first device to a substantiallystraight configuration. The first device may further comprise a guidewire lock that can maintain the position of the guide wire in the guidewire lumen. The method may further comprise the step of locking theguide wire in a position in the guide wire lumen after the step ofpulling the guide wire back through the first device such that thesecond device is adjacent the distal end of the first device.

A third embodiment of the present invention is a method of surgicaldissection of tissue and guiding a second device to a desiredphysiological location with a first device comprising: an elongate shaftcomprising a proximal portion and a distal portion, wherein the distalportion comprises a plurality of segments that articulate with respectto one another and the plurality of segments includes a distal segmenthaving a distal end; a handle attached to the proximal portion of theshaft, wherein the handle comprises controls for articulating theplurality of segments of the distal portion of the shaft with respect toone another; and a guide wire lumen having a proximal and a distal end,wherein the guide wire lumen is disposed along at least a portion of thelength of the first device and the guide wire lumen has openings at boththe proximal and distal ends, comprising the steps of: inserting thefirst device, distal end first, into a first opening in a body with theplurality of segments of the distal portion in a substantially straightconfiguration; advancing the distal portion through the body to dissecttissue; articulating the plurality of segments with respect to oneanother to position the distal portion in a desired physiologicallocation; feeding a guide wire, having a proximal and a distal end, intothe proximal opening of the guide wire lumen, distal end first, andthrough the guide wire lumen until the distal end of the guide wirecomes out the distal opening of the guide wire lumen in the distal endof the first device; connecting the second device to the distal end ofthe guide wire; and pulling the guide wire back through the first deviceand thereby pulling the second device adjacent the distal end of thefirst device at or near a desired physiological location. The method mayfurther comprise the step of: removing the first device through thefirst opening. Prior to the step of removing the first device, thedistal portion of the first device may be returned to the substantiallystraight configuration. The method may further comprise the steps of:disconnecting the second device from the guide wire; and removing thefirst device and the guide wire through the first opening. The seconddevice may be inserted into the body through a second opening in thebody before connecting the second device to the guide wire. The distalend may include an illumination source, and the method further comprisethe step of visually locating the distal end by observing visible energyfrom the illumination source passing through tissue. The illuminationsource may be turned off and on. The desired physiological location maybe with the distal portion of the first device around a pair ofpulmonary veins, and the second device is an ablation device. The firstdevice may further comprise an articulation lock mechanism formaintaining the distal portion of the device in a desired articulatedconfiguration, and further comprising the step of locking the distalportion in the articulated position while the distal portion is in thedesired physiological location. The first device further may furthercomprise an articulation lock mechanism for maintaining the distalportion of the device in a desired articulated configuration, andfurther comprising the steps of: locking the distal portion in thearticulated position while the distal portion is in the desiredphysiological location; and unlocking the distal portion prior toreturning the distal portion of the first device to the substantiallystraight configuration. The first device may further comprise a guidewire lock that can maintain the position of the guide wire in the guidewire lumen. The method may further comprise the step of locking theguide wire in a position in the guide wire lumen after the step ofpulling the guide wire back through the first device such that thesecond device is adjacent the distal end of the first device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is a plan view of an exemplary surgical dissector and guide,shown with an articulated distal portion of shaft, in accordance withthe present invention;

FIG. 2 is a plan view of an exemplary surgical dissector and guide,shown laying on side and with a substantially straight distal portion ofshaft, in accordance with the present invention;

FIG. 3 is a side view of an exemplary distal portion of a shaft of asurgical dissector and guide, shown with a sheath, bands and sheathcoverings removed, in accordance with the present invention;

FIG. 4 is a plan view of an exemplary distal portion of a shaft of asurgical dissector and guide, shown without a sheath, bands and sheathcoverings, in accordance with the present invention;

FIG. 5 is an exploded view of the exemplary distal portion of FIG. 4;

FIG. 6 is an exploded view of components of an exemplary surgicaldissector and guide, in accordance with the present invention, thatcomprise or may be attached to shaft of the exemplary dissector andguide;

FIG. 7 is a plan view of an exemplary distal segment, in accordance withthe present invention, shown with guide wire tube and electrical wiresattached;

FIG. 8 is an exploded view of the exemplary distal segment of FIG. 7;

FIG. 9 is a side view of the exemplary distal segment of FIG. 7;

FIG. 10 is a cross-sectional view of the distal segment of FIG. 9 takenalong the line 10-10 of FIG. 9;

FIG. 11 is a cross-sectional view of a distal portion of a shaft (andsome of proximal portion), in accordance with the present invention,showing the piston assembly;

FIG. 12 is an exploded view of an exemplary piston assembly, inaccordance with the present invention;

FIG. 13 is a plan view, from a distal end, of part of a distal portionof a surgical dissector and guide, in accordance with the presentinvention, showing a view from the distal end of a cross section througha middle segment (segment 22, in particular);

FIG. 14 is a plan view of a handle portion of the exemplary dissectorand guide shown in FIG. 2, in accordance with the present invention,with a top half of a handle housing shown disassembled;

FIG. 15 is a plan view of the handle portion of the exemplary dissectorand guide as shown in FIG. 14 with the top half of the handle housingremoved and a top half of a control wheel and a shaft retainer bothshown disassembled;

FIG. 16 is a top view of the handle portion of the exemplary dissectorand guide as shown in FIG. 15 with the top half of the control wheel,the shaft retainer, and a portion of a guide wire tube removed;

FIG. 17 is a plan view of the handle portion of the exemplary dissectoror guide as shown in FIG. 15 with the top half of the control wheel andthe shaft retainer removed and a shaft, the guide wire tube, a rack, ajam bar, a jam plate and a spring shown disassembled;

FIG. 18 is a plan view of the handle portion of the exemplary dissectoror guide as shown in FIG. 17 with the shaft, the guide wire tube, therack, the jam bar and the spring removed and a portion of a controlwheel lock assembly shown disassembled;

FIG. 19 is a top view of a cam plate (a component of the portion of thecontrol wheel lock assembly shown in FIG. 18);

FIG. 20 is a plan view of the handle portion of the exemplary dissectorand guide as shown in FIG. 18 with the portion of the control wheel lockassembly removed and a pinion, pins, a bottom half of the control wheel,and a guide wire lock shown disassembled;

FIG. 21 is a plan view of the handle portion of the exemplary dissectorand guide as shown in FIG. 20 with the pinion, the pins, the bottom halfof the control wheel and the guide wire lock removed and a power source,power source wires, a power source connector, a PCB, an illuminationsource on-off switch, an illumination source indicator light, a shaftretainer pin, and a power source stabilizer shown disassembled;

FIG. 22 is a top view of a proximal portion of a handle of an exemplarydissector and guide, in accordance with the present invention, shownwith a top half of a handle housing removed;

FIG. 23 is an exploded view of an exemplary guide wire lock, inaccordance with the present invention;

FIG. 24 is a plan view of an exemplary guide member, in accordance withthe present invention;

FIG. 25 is a plan view of a torquer end of the exemplary guide membershown in FIG. 24;

FIG. 26 is a plan view of the torquer end of the exemplary guide membershown in FIG. 24, shown with a tube portion of the guide member removedfrom the torquer;

FIG. 27 is an exploded view of the torquer end of FIG. 26;

FIG. 28 is a plan view of an exemplary dissector and guide, inaccordance with the present invention, with arrows showing rotation of acontrol wheel toward a proximal end of a handle and resultantarticulation or curving of a distal portion;

FIG. 29 is a plan view of the exemplary dissector and guide of FIG. 28,with arrows showing rotation of the control wheel toward a distal end ofthe handle with resultant straightening of the distal portion;

FIG. 30 is an illustration of a chest cavity of a patient from the rightside shown with a thoracotomy and two ports to access the heart showninside, and showing a distal portion of a shaft of an exemplarydissector and guide, in accordance with the present invention, enteringone of the ports;

FIG. 31 is an illustration as in FIG. 30, with a close-up view of theports, heart, throracotomy etc. and showing the distal portion of theshaft of the exemplary dissector and guide inserted and articulatedaround a pair of pulmonary veins on the right side of the heart, and, asindicated by the arrow, an articulation locking mechanism switch movedto prevent the distal portion from straightening;

FIG. 32 is an illustration as in FIG. 31, and showing a guide wire beingfed through a guide wire tube in the exemplary dissector and guide andexiting the distal end of the dissector and guide;

FIG. 33 is an illustration as in FIG. 32, and showing the end of theguide wire that exited the distal end of the dissector and guideattached to a guide member that may be pulled into chest cavity throughthe thoracotomy by withdrawing the guide wire through the guide wiretube (in direction as indicated by arrow);

FIG. 34 is an illustration as in FIG. 33, and showing the guide memberin contact with the distal tip of the dissector and guide, and alsoshowing locking the guide wire in a guide wire lock (by turning lock asindicated by arrow);

FIG. 35 is an illustration as in FIG. 34, and showing an ablation deviceattached to the guide member, which may be moved into the chest cavitythrough the thoracotomy, after the articulation locking mechanism switch(i.e., control wheel lock switch or lock switch) is moved to allowdistal portion to straighten as dissector and guide is withdrawn fromthe port, as a result the ablation device may be pulled into positionaround the pair of pulmonary veins;

FIG. 36 is an illustration as in FIG. 35, and showing the ablationdevice in place around the pair of pulmonary veins (with the guidemember still attached to the ablation device);

FIG. 37 is a cross-sectional side view of a distal portion of a shaft ofan exemplary embodiment of a dissector/guide in accordance with thepresent invention, showing a distal segment articulated;

FIG. 38 is an illustration as in FIG. 37, showing a subsequent step in aprogression of articulation from the distal segment proximally throughmultiple segments; and

FIG. 39 is an illustration as in FIG. 38, showing a subsequent step in aprogression of articulation from the distal segment proximally throughmultiple segments;

FIG. 40 is an illustration as in FIG. 38, showing a subsequent step in aprogression of articulation from the distal segment proximally throughmultiple segments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which is shown by way of illustration specific embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural or logical changes may bemade without departing from the scope of the present invention. Thefollowing detailed description, therefore, is not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims.

With reference to the accompanying figures, wherein like components arelabeled with like numerals throughout the several figures, devices andsystems for surgical dissection and guidance of other medical devices,and methods of use thereof, are disclosed, taught and suggested by themultiple embodiments. It is understood that any of the devices andsystems described may be used for surgical dissection of and/or guidanceof other specialized medical devices to any part of a subject's bodyincluding the human body or that of other animals or creatures. Inparticular, it is contemplated that the devices or systems described areuseful during general, ENT, thoracic, urological, and gynecologicalsurgical procedures, although the applicable procedures are not limitedto those provided. The devices or systems are useful during minimallyinvasive surgical procedures, however they may also be useful in opensurgical procedures.

The present invention is described below as developed for theapplication of providing surgical dissection of tissue and guidance ofablation devices, such as for example, in the treatment of arrhythmiasof the heart, as described above in the Background section. However, thepresent invention is not limited to treatment of arrhythmias of theheart. A device contemplated by the present invention preferablyincludes basic functionality for dissecting tissue in a location in abody and/or guiding another medical device to a location in a body. Sucha device preferably includes a manner of changing the shape of a distalportion of the device in order to dissect tissue. Such a device alsopreferably includes a manner of changing the shape of a distal portion(e.g., curved shape) for positioning the distal portion of the device ina desired anatomical location (e.g., around a blood vessel) in a body.In addition, such a device preferably includes a manner of straighteninga distal portion of the device in order to fit though a surgical port.Further, such a device may provide a manner of locking a distal portionin a certain shape or curvature and/or may prevent the distal portionfrom being straightened once the distal portion has a desired shape.Preferably, shape of a distal portion is controlled from a proximalportion of the device, which may be located outside of the body (i.e.,ex vivo) while the distal portion is inside the body. Also preferably,the ex vivo controls for changing the shape of the distal portion of thedevice may provide an operator with information about the shape of thedistal portion while the distal portion is in vivo. Such a device alsopreferably includes a manner of illuminating the distal portion forpurposes of identifying its location, which is relevant for dissectionof tissue and/or proper placement of another device. Still further, sucha device may be part of a system for guiding another medical device to alocation in a body.

With reference initially to FIG. 1, a preferred embodiment of a surgicaldissector and guide 10 (hereinafter referred to as “dissector”), inaccordance with the present invention, is illustrated having, generally,an elongate shaft 12 and a handle 14. In the case of ablation deviceprocedures, the shaft 12 may be sized and shaped to preferably allow theshaft 12 to be inserted into the thoracic cavity through a trocar port(e.g., 10 mm or 12 mm). However, the device may be differently sized tobe inserted through other orifices, such as a small thoracotomyincision, e.g., roughly 1 cm, and/or various other incisions. The shaft12 comprises a distal portion 16 and a proximal portion 18. The distalportion 16, as seen in FIG. 1, preferably comprises a plurality ofsegments that are interconnected and articulable. In the FIG. 1embodiment the distal portion 16 is illustrated as comprising foursegments, which include a distal segment 20, and three middle segments22, 24, 26. The third middle segment 26 is connected to a distal end 28of the proximal portion 18 of the shaft 12. The distal segment 20preferably includes a distal tip 30. The distal tip 30 of the shaft 12may be smooth and convex in shape so as not to cause unintended tissuedamage when the distal tip 30 is manipulated through tissue. The distaltip 30 preferably also includes an illumination source 32. A proximalend 34 of the proximal portion 18 is preferably rigidly retained by orattached to the handle 14 at the distal end 36 of the handle 14.

The purpose of the illumination source 32 (e.g., a light) may be toallow visualization of the location and placement of the distal portion16 within a body. The illumination source 32 may provide sufficientillumination to visualize tissue and confirm the placement of the distalportion 16 of the shaft 12 of the dissector 10. Preferably, theillumination source 32 comprises an LED. Depending on any particularapplication, other illumination or light sources are also contemplated.The illumination source 32 may provide directional, non-diffuse light,e.g., white in color, with a divergent beam including angle of less thanabout 45 degrees. The illumination source 32 may, according to apreferred embodiment, provide a light intensity that allows desiredillumination of pericardial tissue, for example, with a measurable rangeof preferably about 5 to 30 foot-candles. However, a larger range ofillumination is also contemplated by the present invention, which may befrom about 1 to 1,000 foot candles. Preferably, the illumination source32 will not generate sufficient heat to raise the distal tip 30 andsurrounding tissue to greater than about 41° C. for use in heart tissue,in particular.

The handle 14 of the dissector 10 shown in FIG. 1 provides a handheldhousing for components that may control the functions of the dissector10, such as for articulation of the distal portion 16 and illuminationof the illumination source 32. The handle 14 shown in FIG. 1 comprises ahousing 38, an illumination source on/off switch 40 (the switch 40 mayallow the illumination source 32 to be turned on and off during aprocedure), an illumination source indicator light 42, a control wheel44, a lock switch 46, and a guide wire lock 48 on the proximal end 50 ofthe handle 14. The handle 14 may be designed to be used by an operatorin their right or left hand.

As discussed above, generally, the dissector 10 comprises an elongateshaft 12 attached to a handle 14, with the shaft 12 comprising distal 16and proximal 18 portions. In particular, the distal portion 16 of theshaft 12 will be discussed in more detail. The distal portion 16preferably changes shape in order to dissect tissue and/or to bepositioned in a desired anatomical location. Also, the distal portion 16preferably may also have a substantially straight configuration in orderfor the distal portion 16 to fit through a surgical port.

FIG. 1 illustrates the distal portion 16 with segments 20, 22, 24, 26articulated with respect to one another, and with respect to theproximal portion 18. The purposes of such articulation or movement mayinclude, but not be limited to, to help steer the end of the dissector10 around anatomical structures, to help dissect tissue, and to helpposition the illumination source 32 behind and around the anatomicstructures of a beating heart, for example, with the handle 14 ex vivo.Different amounts of selective and controlled articulation or movementof the distal portion 16 by a user are possible, thereby allowing thedistal portion 16 to accommodate patients that vary in size and anatomicstructures. Also, different embodiments of the distal portion 16 of theshaft 12 are contemplated by the present invention, including, forexample, embodiments including more or less numbers of segments, usingsegments of different lengths and sizes together or as similarvariations and different attachment means between such segmentsproviding any degree of segment-to-segment or segment-to-portion 18articulation, such that the distal portion 16 is able to articulate froma substantially straight configuration to arcuate shapes of variousconfigurations and degrees of curvature and vice versa. An arcuate shapeor curve may have constant radius or changing radius as controlled atleast in part by the connection between segments and proximal portion 18as to be understood from the description of those components below.

FIG. 2 illustrates another possible shape or configuration of the distalportion 16, which is with the segments 20, 22, 24 and 26 (not shown, butcovered with sheath) arranged as a substantially straight configurationor shape. A purpose of such a substantially straight shape is to allowthe shaft 12 to be both easily inserted into and easily withdrawn from abody through a port having a small diameter, such as a 10 mm trocar portor a 12 mm trocar port, as examples.

In order to help prevent the components of the distal portion 16 of theshaft 12 from inadvertently catching on tissue or compressing tissuewhile the device is inserted into or during use within a body, thedistal portion 16 (and possibly also a portion of the proximal portion18) of the dissector 10 may be preferably covered with a sheath 52comprising a flexible material, such as silicone, for example (althoughother materials are also contemplated). Any material that is flexible orhas an elasticity to permit the degree of articulation of the segments,and that is suitable for a given application, is contemplated. FIGS. 2-4illustrate embodiments that include such a sheath 52. In order to holdthe sheath 52 in place on the shaft 12, the ends of the sheath 52 areillustrated as preferably covered with bands 54 preferably comprising aheat shrinkable material that is heat shrunk around the ends of thesheath 52. A suitable band material comprises a heat shrinkablepolyester, although other materials are also contemplated by the presentinvention as may be suitable for different applications.

FIG. 3 shows the distal portion 16 of the shaft 12 with the sheath 52and bands 54 disassembled from the distal portion 16 of the shaft 12. Inaddition, FIG. 3 includes three segment coverings 56 that preferablycomprise a heat shrinkable material (e.g., like that comprising thebands 54). The segment coverings 56 cover each of the three middlesegments 22, 24, and 26, and are located over the segments 22, 24, 26and under the sheath 52. The purpose of the segment coverings 56 is tohold certain components of the distal portion 16, which run through thethree segments 22, 24, 26, together (which will be discussed in moredetail below).

FIG. 4 shows a distal portion 16 of an exemplary shaft 12, in accordancewith the present invention, shown with a sheath 52, bands 54 or segmentcoverings 56 removed, as the segments 20, 22, 24, 26 may be provided.FIG. 5 shows the distal portion 16 of FIG. 4 in an exploded view.

In order to allow the segments of the distal portion 16 to articulatewith respect to one another and with respect to the proximal portion 18of shaft 12, articulating connection joints are provided between thesegments. In particular, tongue and groove joints 58 are shown in FIG. 5as pivotally connecting the segments 20, 22, 24, 26 and segment 26 tothe distal end 28 of the proximal portion 18 of the shaft 12. Althoughtongue and groove joints 58 are shown in FIG. 5, other articulatingconnection joints as known or developed in the future may instead beused that allow for movement and/or articulation of the segments withrespect to one another, and as such are also contemplated by the presentinvention. For example, another possible articulating connection jointthat may be used in the present invention is a ball and planar,socket-like joint that is kept under tension. Other such suitablearticulating connection joints are also contemplated.

The tongue and groove joints 58 comprise: tongue portions 60 on thedistal ends of the respective segments 22, 24, 26 and the distal end 28of the proximal portion 18 of the shaft 12; and, groove portions 62 onthe proximal ends of the segments 20, 22, 24, 26 provided by spacedelements 63. Holes 64 are preferably provided through the tongueportions 60 and the elements 63 of groove portions 62 which may bealigned to be coaxial such that pins 66 inserted through the holes 64may pivotally attach or connect the tongue 60 and groove 62 portions ofthe joints 58. Such joints 58 are preferably integrally made withsegments but could be otherwise provided. As shown, such tongue andgroove joints 58 provide a sufficient degree of rotation betweenadjacent components to permit controlled shaping of the distal portion16, in accordance with the present invention. Such degree of rotationcan be otherwise limited or enhanced to a greater degree by modifyingdesign features of the tongues and grooves or by substituting othercontemplated articulating connection joints.

The elongate shaft 12 of the dissector 10 comprises the distal portion16 as well as the proximal portion 18. More detail of the articulatingdistal portion 16 and components that extend through the proximalportion 18 to the handle 14 is given below. A purpose of the proximalportion 18 is to provide a shaft through which components may extendbetween the distal portion 16 and the handle 14. Another purpose of theproximal portion 18 is to lengthen the shaft 12 so that the articulatingdistal portion 16 may reach farther into a body with the handle being exvivo.

FIG. 6 shows an exploded view of the shaft 12 and components that extendthrough the shaft 12 and into or through the handle 14 (some componentsnot shown in previous Figs.). Beginning at the most distal segment 20,the embodiment in FIG. 6 shows a flexible guide wire tube 68 that fitswithin an opening 72 in the end of the distal tip 30 of the distalsegment 20 (not shown in FIG. 6, but can be seen in FIG. 10 as 72) andthat extends through groove 91 (as seen in FIG. 5), defined cumulativelyas running lengthwise through the segments 22, 24, 26, and the proximalportion 18 of the shaft 12, as assembled in series. Preferably, each ofthe segments 20, 22, 24, 26 (and any number of more or less segments)includes (as seen in FIG. 4) a groove 91 along and open to the outsideof each segment 20, 22, 24, 26, creating an opening for access andcontaining internally passing elements, such as the guide wire tube 68and electrical wires 76 as described below. Distal segment 20 preferablyhas such a groove 93 that only partially extends along its surface tofacilitate tube 68 to the opening 72, as shown in FIGS. 4 and 10. Themiddle segments 22, 24, 26 preferably have such a groove 91 that extendsover the respective lengths thereof with proximal most middle segmentreceiving elements like tube 68 from an internal passage (not shown) ofsuch proximal portion 18, while internal passage is preferably definedentirely through the shaft portion 18 to facilitate passage of the guidewire tube 68 extending to the distal tip 30. Discussion relating tolater figures illustrating the handle 14 will describe how the guidewire tube 68 extends through the handle 14.

Another groove 111, like groove 91 for the guide wire tube 68, is alsopreferably located open and to the outside of the segments 22, 24, 26 ofdistal portion 16, and preferably contains the electrical wires 76. Aportion of the groove 111 can be seen in FIG. 13, discussed below. Thediscussion above with regard to the groove 91 for the guide wire tube 68also preferably applies to the groove 111 for the electrical wires 76.

The guide wire tube 68 preferably comprises a coiled wire tube made of304 stainless steel (SS). The purpose of the guide wire tube 68 is toprovide a lumen in which a guide wire may be retained or passed throughthe dissector 10. The guide wire tube 68 preferably comprises a flexiblematerial or has a design that provides flexibility such that the guidewire tube 68 is able to articulate or move with the segments of thedistal portion 16 of the shaft 12 without closing off the lumen insidethe tube 68 or restricting movement of a guide wire retained in the tube68. Any other materials or designs that may provide such a flexible tubeare also contemplated by the present invention.

In order to provide power to the illumination source 32 in the distaltip 30, preferably two electrical wires 76 connect the illuminationsource 32 in the distal tip 30 of the distal segment 20 to a powersource, which is preferably located in the handle 14. FIG. 6 shows thatthe electrical wires 78 extend from the distal tip 30 (i.e., LEDhousing), through the grooves 111 in each respective segment (andthrough a groove in the distal segment 20, which is not seen in anyfigures), and through the proximal portion 18 of the shaft 12 to thehandle 14. Discussion relating to later figures illustrating the handle14 will describe how the electrical wires 76 are connected to a powersource in the handle 14.

More detail of the distal segment 20 as comprising the distal tip 30 anda recessed portion 80, and how other components extend there from, canbe seen in FIGS. 7-10. FIG. 7 shows the distal segment 20 assembled withguide wire tube 68 and electrical wires 76 connected. FIG. 8 is anexploded view of FIG. 7. FIG. 9 is a side view of the distal segment ofFIG. 7, and FIG. 10 is a cross section of FIG. 9. Together, FIGS. 7-10illustrate that the illumination source 32 is preferably placed in acavity 78 in the distal tip 30 that is open at the tip for theillumination source 32 to pass through. A proximal side of the distaltip 30 fits over and connects to the distal end of the recessed portion80 of the distal segment 20. The guide wire tube 68 is shown extendingthrough groove 93 of the recessed portion 80 and the distal tip 30. Theelectrical wires 76 are shown preferably soldered to the lead end 82 ofthe illumination source 32. A pin 84 holds illumination source 32 inplace by extending through coaxially aligned holes 86, 88 located on therecessed portion 80 of the distal segment 20 and the distal tip 30,respectively, and by retaining the illumination source 32 between therecessed portion 80 and distal tip 30.

In order to cause controlled articulation of the segments of the distalportion 16 with respect to one another, a piston assembly 98 (FIG. 6) ispreferably disposed within the distal portion 16 and connectedproximally to a push/pull rod 92 that extends through the proximalportion 18 and into the handle 14, where controls (which will bediscussed later) are present to push or pull the rod 92 whichstraightens or articulates the pistons and segments. Referring back toFIG. 6, the figure shows a set of three pistons 90, that are part of thepiston assembly 98, and that are lined up end-to-end and pivotallyconnected. The pistons 90 are also attached to a push/pull rod 92 at theproximal end 94 of the set of pistons 90. The piston assembly 98 is alsopreferably disposed within pistons lumens (one of which shown in FIG. 13as 109) through the segments 22, 24, 26, as shown in FIG. 11. FIG. 11shows that the pistons 90 are pivotally connected and extend lengthwisethrough (one each) the three middle segments 22, 24, 26 of the distalportion 16 of the shaft 12. Each of the three pistons 90 is generallyslidably disposed within a respective one of the three middle segments22, 24, 26. The distal end 96 of the piston assembly 98 is preferablypivotally connected to the recessed portion 80 of the distal segment 20,and the proximal end 94 is pivotally connected to the push/pull rod 92.

In order to allow the pistons 90 of the piston assembly 98 to articulatewith respect to one another and with respect to the distal segment 20and push/pull rod 92, articulating connection joints are providedbetween the components. In particular, FIG. 12 illustrates jointscomprising grooves 100 and links 104 connected by pins 106. Articulatingconnection joints, other than those shown in FIG. 12, that allow formovement and/or articulation of the pistons 90 with respect to oneanother and the other components, could be used and are alsocontemplated by the present invention. FIG. 12 shows that on both theproximal and distal ends of the pistons 90 there is a groove 100 withtwo coaxially aligned holes 102 on spaced elements 103. The pistons 90are preferably connected together, to the recessed portion 80 of thedistal segment 20, and to the push/pull rod 92, using links 104including two holes 107, which are connected to the pistons 90 (andother applicable components) by inserting pins 106 through coaxiallyaligned holes 102, 107 through the elements 103 and links 104,respectively. The articulating connection joints described provide asufficient degree of rotation between adjacent components to permitcontrolled shaping of the distal portion 16, in accordance with thepresent invention. Such degree of rotation can be otherwise limited orenhanced to a greater degree by modifying the design features of thedescribed joints or by substituting other contemplated articulatingjoints.

FIG. 13 illustrates a cross section of a middle segment, in particularsegment 22. As illustrated in the embodiment shown in FIG. 13, one ofthe pistons 90 is disposed in a piston lumen 109 in segment 22, with thepiston lumen 109 preferably running in the axial direction as shown andalso radially offset as shown (with the dissector in the orientationshown in FIG. 1). The arrangement of the piston assembly 98 in thedistal portion 16, with the pistons assembly 98 being axially offset asshown in FIG. 13, results in articulation of the segments of the distalportion 16. When the push/pull rod 92 is pulled proximally, the pistons90 begin to articulate (curve upward as shown in FIG. 1) beginning withthe most distal piston 90. So, preferably, the segments 20, 22, 24, 26articulate beginning with the distal segment 20. As the distal portion16 is straightened (when push/pull rod 92 is pushed distally), thesegments 20, 22, 24, 26 straighten in the reverse order, beginning withthe most proximal segment that is articulated.

FIGS. 37-40 illustrate an exemplary, preferred progression of thearticulation of the segment of the distal portion 16 of the shaft 12.FIG. 37 shows the distal segment 20 first articulated when the push/pullrod 92 is pulled proximally and a link 104 lines up with the joint 58between the distal segment 20 and middle segment 22 and is able toarticulate with the joint 58. Next, FIG. 38 shows that as the push/pullrod 92 is pulled proximally farther, the middle segment 22 alsoarticulates when the link 104 on its proximal end lines up with thejoint 58 between the middle segment 22 and segment 24. FIGS. 39 and 40show subsequent steps as the push/pull rod 92 is pulled proximally untilall segments 20, 22, 24, 26 are articulated with respect to the proximalportion 18 of the shaft 12.

The progression of articulation of the segments, as described above, ispreferred for the embodiment described herein. However, otherprogressions are also contemplated by the present invention. Forexample, the segments could articulate from the proximal-most segment tothe distal-most segment. This alternative progression of articulationcan be possible if the lengths of the pistons 90 and links 104 arereconfigured to change the order in which the segments articulate. Also,other progressions are also possible with the segments articulating inany desired order by reconfiguring the lengths of the pistons 90 andlinks 104.

The embodiments of the invention illustrated in the figures show thesegments articulating in the same general plane. However, it is alsocontemplated by the present invention that one or more of the segmentsmay articulate out-of-plane. This could be possible by rotating theorientation of the joint 58 between adjacent segments. Such out-of-planerotation of a segment(s) (e.g., the distal segment 20) could beadvantageous for certain anatomy.

So as to reduce friction between the segments 22, 24, 26 and the pistons90, a lubricious coating or a sheath is preferably coated, attached ordeposited onto the pistons 90 and/or inside piston lumens 109. FIG. 12shows three sheaths 108 that are preferably placed over each of thethree pistons 90. The three sheaths 108 preferably comprisepolytetrafluoroethylene (PTFE) heat shrink tubing cut to length,although other suitable materials may also be used. An alternative tothe sheath 108, which is also contemplated by the present invention, isa lubricious coating coated or deposited onto the pistons 90 and/orinside of the piston lumens in the segments 22, 24, 26. Some examples ofsuch lubricious coatings include, but are not limited to, Dicronite™,silicone, Teflon™, and other suitable polymers. The purpose of suchcoatings or sheaths is to reduce friction that occurs between similarmaterials rubbing on each other.

In order for the distal portion 16 of the dissector 10 to articulate asdesired, the present invention is not limited to the assembliesdiscussed above. For example, instead of a piston assembly 98 disposedin the segments, a different assembly may be used. In the othercontemplated assembly, stainless steel spring temper ribbon wire may beused. The ribbon wire may have varying thickness along the ribbonallowing for control of bending of the ribbon wire at certain locationsalong its length. For example, thinner sections of ribbon wire would bedisposed in joint areas between segments of a distal portion 16. Inaddition, the ribbon wire may be over-molded with a lubricious materialwhere the ribbon wire is disposed in the segments of the distal portion16, so that the ribbon wire would be able to move through the segments.The described ribbon wire assembly could be pinned at both ends to therespective segments. Other configurations that allow for such movementof segments in the distal portion 16 are also contemplated by thepresent invention.

FIG. 13 also illustrates an example of how the guide wire tube 68 andthe electrical wires 76 may extend through the segments 22, 24, 26. Theguide wire tube 68 is shown extending through groove 91, which is alsopreferably radially offset, and the electrical wires 76 are shownextending through groove 111, which is also preferably radially offset(at a different location though).

The guide wire tube 68, electrical wires 76 and the push/pull rod 92extend proximally through the tubular shaft housing 110 that comprisesthe proximal portion 18 of the shaft 12, and into the handle 14. Inparticular, the electrical wires 76 and push/pull rod 92 allow for theillumination source 32, and the articulating pistons 90 and segments inthe distal portion 16 of the shaft 12 to be controlled proximally fromthe handle 14. The tubular shaft housing 110 provides a lumen 113through which the other components may extend to the handle 14.

Referring back to FIG. 6, some components, that are located in thehandle 14, are shown attached to the proximal end of the push/pull rod92. The proximal end of the push/pull rod 92 is rigidly attached to arack 112. The purpose of the rack 112 is to linearly move the push/pullrod 92 back and forth in the dissector 10, which in turn can articulateor straighten the piston assembly 98, and, ultimately, can articulate orstraighten the segments 20, 22, 24, 26 of the distal portion 16 withrespect to one another and the proximal portion 18 of the shaft 12. Therack 112 is preferably aligned such that the rack 112 moves back andforth along the length of the dissector 10. The rack 112, is preferablya generally oval-shaped component, as shown, with a set of teeth 114 onan inner surface 116 of the rack 112. In order to move the rack back andforth other components found in the handle 14 cooperate with the rack112. The other components will be discussed below with regard todescription involving figures illustrating the handle 14.

FIG. 6 also shows a link 118 and a jam bar 120. The link 118 ispreferably a male threaded connector that screws into female voids (notshown), one such void in each of the rack 112 and the jam bar 120, andconnects the rack 112 and jam bar 120 together. The purpose of the jambar 120, and how it cooperates with other components, will also bediscussed below.

Details regarding the handle 14 and any exemplary enclosed or attachedcomponents will be discussed below. FIG. 14 illustrates generally anexemplary handle 14 (also shows part of the proximal portion 18 ofshaft), in accordance with the present invention, shown with the tophalf 38 a of the handle housing 38 removed.

FIG. 15 is the same handle portion as shown in FIG. 14 with the top half38 a of the handle housing 38 removed and a top half 44 a of the controlwheel 44 and a shaft retainer 122 both shown disassembled. Whenassembled, the shaft retainer 122 is held in place in the handle 14 bytwo screws 124, and functions to rigidly attach the shaft 12 to thehandle 14. The top half 44 a of the control wheel 44 fits with thebottom half 44 b over a dowel pin 126, and both halves 44 a, 44 b areheld in place by the two halves 38 a, 38 b of the handle housing 38. Thecontrol wheel 44 rotates, which functions to move a pinion 126 withrespect to the rack 112, which controls back and forth motion of thepush/pull rod 92 and articulation and straightening of the distalportion 16 of the shaft 12 (more details of the components relating tothe control wheel 44 will follow). In the particular embodiment shown inFIG. 15, washers (one shown as 128 and the other hidden in FIG. 15)provide space between the halves 44 a, 44 b of the control wheel 44 andthe handle housing 38 such that the control wheel 44 may be allowed torotate. However, other methods of allowing rotational movement of thecontrol wheel 44 are also contemplated by the present invention.

FIG. 16 is a top view of the handle 14 portion as in FIG. 15. FIG. 16shows how the teeth 114 on the rack 112 cooperate or fit together with aset of teeth 130 on a pinion 132. The pinion 132 includes a notch 134into which a pin 136, also connected to both halves 44 a, 44 b of thecontrol wheel 44, fits and holds the pinion 132. The pin 136 and notch134 provide a way for the pinion 132 to move together with the controlwheel 44 when rotated. Therefore, rotation of the control wheel 44 alsorotates the pinion 132, which, through the cooperating sets of teeth114, 130, moves the rack 112 backward and/or forward along the length ofthe dissector 10, which in turn pulls or pushes the push/pull rod 72such that the attached pistons 90, and the corresponding segments 22,24, 26, in which the pistons 90 are disposed, articulate or arestraightened with respect to one another.

In order to lock the distal portion 16 of the shaft 12 in a desiredcurve and/or in a substantially straight configuration, a lockingmechanism is provided in the dissector 10 to selectively hold thepush/pull rod 72 axially in an axial position. Locking the distalportion 16 in a desired configuration may be desired during certainprocedures and in certain anatomical regions of a body. FIG. 16,together with FIGS. 17 and 18, illustrate an exemplary locking mechanism(i.e., an actuation mechanism lock) that may be used to hold the controlwheel 44 in place and thereby hold the rack 112, push/pull rod 72, andthus the distal portion 16 of the shaft 12, in a desired configuration.In particular, the locking mechanism in the embodiment shown in FIGS.16-18 comprises a friction lock. In general, it is desired that anylocking mechanism used would preferably lock the distal portion 16 ofthe dissector 10 in a desired configuration and also unlock.

FIGS. 16-18 together show a friction lock and its components. The jambar 120, which is attached to the rack 112, may extend through anaperture 138 in a jam plate 140.

The aperture 138 shown (FIG. 17) has a square shape, but other shapesare also contemplated (e.g., circular). The purpose of the aperture 138is to allow the jam plate 140 to either contact the jam bar 120 or not,which locks or unlocks, respectively, the friction lock. The aperture138 preferably has a diameter or other applicable dimension(s) that areslightly larger than the outer diameter or dimension of the jam bar 120to allow the jam plate 140 (i.e., friction lock) to slide along the jambar 120. A spring 142 surrounds the jam bar 120 on the proximal side ofthe jam plate 140. The purpose of the spring 142 is to maintaincompression, as the dissector 10 may be used in various orientations.The jam bar 120, jam plate 140 and spring 142 are disposed in a housing144. The jam bar 120 is shown extending through two channels 146 in thehousing 144. The jam plate 140 and spring 142 are also disposed withinthe housing 144. The housing 144 is attached to the lower half of thehandling housing 38 b by two screws 148.

FIG. 18 provides an exploded view of a portion of the locking mechanism,as in FIG. 17, with the rack, 112, jam bar 120, jam plate 140 and spring142 removed. The portion of the locking mechanism in FIG. 18 showscomponents that may function to move the jam plate 140 so the jam plate140 either contacts the jam bar 120 or allows the jam bar to movethrough the aperture 138 in the jam plate 140, which locks or unlocksthe friction lock, respectively. FIG. 18 illustrates that the lockswitch 46 attaches to a cam plate 150 using a screw 152. The cam plate150 and lock switch 46 together can move back and forth in an opening154 in the handle housing 38 b, which is oriented along the length ofthe dissector 10, in order to activate or inactivate the lockingmechanism for the control wheel 44. In the exemplary locking mechanismshown in FIGS. 16-18, when the lock switch 46 is in a locked position,or moved toward the proximal end 50 of the handle 14, a follower plate156 with an attached follower pin 158 are moved toward the jam bar 120so the follower pin 158 allows the jam plate 140 to tilt against anotherpin 163 and frictionally engage the outer surface of the jam bar 120.The follower plate 156 includes grooves 160 that mate with grooves 162(as shown) on a rail plate 164 that is attached to the bottom half 38 bof the handle housing 38. As seen in FIG. 19, which shows the cam plate150, there is a slot 166 in the cam plate 150 in which the follower pin158 rides (the slot being angled at about a 45 degree angle from thedirection that the cam plate 150 moves along the length of the dissector10, with the general direction being indicated by the double-ended arrowin the figure). As the cam plate 150 is slid along the length of thedevice, the described configuration results in the follower plate 156and pin 158 moving generally perpendicular to the direction of the lockswitch 46 and cam plate 150 (which is along the length of dissector 10).The result is that the follower pin 156 may be pushed against the jamplate 140 in such a way to move the jam plate 140 to either allow thejam bar 120 to pass through the aperture 138 or not. When the lockswitch 46 is in an unlocked position, or moved toward the distal end 36of the handle 14, the follower pin 158 is moved away from the jam bar120 through the slot 166 in the cam plate 150, which moves the jam plate140 such that the jam bar 120 is able to move freely though the aperture138 in the jam plate 140. A purpose of the configuration chosen for thelocking mechanism is to translate movement of the switch 46 that goesalong the length of the dissector 10 to movement that is perpendicularto the movement of the switch 46.

In the exemplary embodiment of the locking mechanism described above,once the dissector 10 is properly positioned, the locking mechanism maybe activated. In this preferred embodiment, the control wheel 44 maystill be rotated to further articulate the segments of the distalportion 16, but the control wheel 44 cannot be rotated in a direction tostraighten the segments. Other embodiments are, however, contemplatedthat would also include preventing further articulation of the segmentswhen a locking mechanism is activated.

The exemplary locking mechanism described above is just one example of alocking mechanism that may be used in the present invention, and manyother locking mechanisms are also contemplated by the present invention(e.g., a ratchet system or a cam mechanism).

FIG. 20 is the same embodiment of the handle 12 as in FIG. 19, exceptthe locking mechanism components of FIG. 19 are removed, and the pinion132, dowel 126, lower half of the control wheel 44 b, a washer 168, afemale luer 169, and the guide wire lock 48 are shown disassembled. Thefigure illustrates a second washer 168 that is placed on the dowel pin126 between the lower half 38 b of the handle housing 38 and the lowerhalf 44 b of the control wheel 44 such that, along with the other washer128 (in FIG. 15), the control wheel 44 may be free to rotate inside thehandle housing 38 on the pin 126. The purpose of the second washer 168,just like the first washer 128, is to allow the control wheel 44 torotate freely with respect to the handle housing 38 (38 b in particularwith respect to the second washer 168). FIG. 20 also illustrates thatthe guide wire lock 48 is retained in the handle 14 by being attached tothe female luer 169 that is held between a guide wire lock retainer 170and the top half 38 a (not shown) of the handle housing 38.

FIG. 21 is an exemplary portion of the device shown in FIG. 20 with thecomponents shown disassembled in FIG. 20 removed in this figure, andwith a printed circuit board (PCB) 172, the illumination source on/offswitch 40, the illumination source indicator light 42, a shaft retainerpin 174, a power source 176, a power source connector 178, power sourcewires 180, and a power source stabilizer 182 shown disassembled from thebottom half 38 b of the handle housing 38. The purpose of the powersource 176 is to provide power for the PCB 172, and ultimately theillumination source 32 and illumination source indicator light 42. Thepower source 176 in the portion of the exemplary dissector 10 shown inFIG. 21 is a 9-volt battery. Other power sources, however, are alsocontemplated by the present invention. Preferably, the power source 176is a disposable battery. The disposable battery may be a disposablelithium battery. The power source 176 may be capable of powering theillumination source 32 and the illumination source indicator light 42 toa desired intensity for any determined time period. The power source maybe removable. The connector 178 and the power source wires 180, in thepreferred embodiment shown in the figure, extend and attach to the PCBcircuit 172. Electrical wires (not shown in the figure) extend from thePCB circuit 172 to the illumination source indicator light 42 and (wires76) to the illumination source 32 in the distal tip 30 of the shaft 12.In order to stabilize the power source 176 in the handle housing 38 andprevent movement of the power source 176 in the handle 14, the powersource 176 may be attached to the power source stabilizer 182, as inFIG. 21. The power source stabilizer 182 may comprise, for example, afoam spacer (as shown in figures), hot glue, a spring, or any othersuitable material or form for a given application. FIG. 21 also includesthe shaft retainer pin 174 that prevents the tubular shaped shaft 12from rotating.

FIG. 22 is a top view of a portion of the handle 14 near the proximalend 50 shown with the top half 38 a of the handle housing 38 removed.The figure illustrates that the guide wire tube 68, in the exemplaryembodiment, extends through the handle 14 such that it extends by thepower source 176 toward the top half 38 a of the handle housing 38. Thefigure also illustrates how the guide wire tube 68 extends into thefemale luer 169. A guide wire may continue out the opening 74 through alumen 181 in the female luer 169 and through a lumen 183 in the guidewire lock 48 to the proximal opening 74.

Another feature of the present invention is that the dissector 10 mayinclude an indicator, preferably on the handle 14, to indicate to theuser to what extent the distal portion 16 is curved or articulated. Thepurpose of such an indicator is to inform the user of the amount ofcurvature of the distal portion 16, which may be important for a givenprocedure or with regard to a particular anatomical position. Forexample, the control wheel 44 may have tactile features that indicate tothe user to what extent the distal portion 16 of the shaft 12 isdeflected or articulated. Additionally, or alternatively, the handle 12may include a graphical angle indicator or indicators that coordinatewith the rotation of the control wheel 44 to indicate the amount ofarticulation of the distal portion 16, such as that shown as 230 inFIG. 1. In the embodiment shown in FIG. 1, as the control wheel 44 isrotated, an indentation on the control wheel 44 may generally line upwith one of three graphical indicators 230, which graphically illustratethe approximate amount of articulation of the distal portion 16 of theshaft 12. Other types of indicators are also contemplated by the presentinvention.

FIG. 23 is an exploded view of the exemplary guide wire lock 48. Apurpose of the guide wire lock 48 may be to hold or lock (and alsorelease or unlock) a guide wire positioned through the guide wire tube68 of dissector 10 in a desired position or location. A purpose forlocking the guide wire in place is discussed below with regard to amethod embodiment of the present invention. The exemplary guide wirelock 48, although other embodiments are also contemplated, comprises afitting 184, a washer 186, a collet 188, an insert 190, and a knob 192.A lumen 183 extends through each of the components of the guide wirelock 48, providing a space for a guide wire to move through the guidewire lock 48. However, a portion of the lumen 183 may also be closed ifthe guide wire lock 48 is in a locked configuration. A guide wire may belocked into a position, for example, by turning the knob 192 clockwise,which tightens the lock 48 around the guide wire. In particular, thefitting 184 and knob 192 are cooperatively threaded (not shown) suchthat when the knob 192 is turned clockwise, it moves closer to thefitting 184, which in turn moves the collet 188 into the insert 190. Thecollet 188 has any number of slots such that when the collet 188 ismoved into the insert 190 the collet 188 is radially compressed. Thecollet 188 is also preferably made of a lubricious polymer (e.g.,Delrin™, PEEK™, or certain grades of nylon), such that the collet 188 isable to move as necessary within the other components of the guide wirelock 48. Therefore, if a guide wire extends through the lumen 183 thatruns through the collet 188, the guide wire may be held in place by thecompressed collet 188.

The dissector 10, as described above, may be used to dissect tissue.Additionally, or alternatively, the dissector 10 may be part of asystem, including other components or devices, used to guide anothermedical device into a desired location in a body. Other components ordevices that may be used with the dissector 10 comprise a guide wire(example is 218 in FIGS. 32-35), a guide member 194, and another medicaldevice (e.g., an ablation device 222 as in FIG. 35) that is to be placedin a location in a body.

In general, the guide wire, as part of the system, may be used to guidea medical device to a desired location in a body. More detail of how theguide wire is used in the system in accordance with the presentinvention is provided below. However, in general, a distal end of theguide wire is fed through the guide wire tube 68 in the dissector 10from opening 74 and out through opening 72, after the distal portion 16of the dissector 10 is in a desired location in a body. The distal endof the guide wire may then be attached to the guide member 194 (havingfirst and second ends) at a first end and then withdrawn back throughthe guide wire tube 68 until the guide member 194 comes near or intocontact with the distal tip 30 of the dissector 10. The guide wire isthen locked using the guide wire lock 48, and the dissector 10 and guidewire, with guide member 194 attached are withdrawn back through an portof entry. The dissector 10, guide wire and attached guide member 194 maypull another medical device, which may be attached to the second end ofthe guide member 194, into the location in the body where the distalportion 16 of the dissector 10 was located prior to withdrawal.

In the present invention, any type of known or future developed guidewire may be used with the system. An exemplary guide wire is a floppy,straight-tip, 0.035″ guide wire. The guide wire may include markings togauge the amount of guide wire being extended through and out from thedissector 10, which can assist in medical device placement procedures,for example.

FIG. 24 illustrates an exemplary guide member 194. The purpose of theguide member 194 is to guide a medical device to a desired location. Aspart of the system, in accordance with the present invention, the guidemember attaches, at one of two ends, to a guide wire that is withdrawnback through the dissector 10 through which the guide wire is fed. Thesecond end of the guide member 194 is preferably attached to a medicaldevice that is desired to be placed in a body. Therefore, when the guidewire is withdrawn, the guide member is pulled into the body adjacent thedistal tip 30 of the dissector 10. The guide wire is locked in place inthe dissector 10 and then the dissector and wire are withdrawn, whichpulls the guide member through, and ultimately pulls a medical devicethat may be attached to the second end of the guide member into adesired location in a body.

The exemplary guide member 194 comprises an elongate tube 196 with atorquer 198 on a first end 207 of the tube 196 (having first 207 andsecond 208 ends). FIG. 25 illustrates the end of the guide member 194including the torquer 198. The torquer 198 has configurations such thatit may retain guide wire and may, with a change in configuration,release the guide wire. FIG. 26 includes the same portion of the guidemember 194 as in FIG. 24 with the torquer 198 removed from the tube 196.FIG. 27 is an exploded view of the torquer 198, which comprises atorquer body 220, collet 202, and torquer tip 204. The tapered end 206of the torquer body 200 preferably fits inside the tube 196 in order tohold the torquer 198 in place in the tube 196. The guide wire member194, preferably, may be used to lock and release an end of a guide wirein the torquer 198 or may otherwise be capable of attaching or couplingto the distal portion 16 of the dissector 10. Moreover, the guide wiremember 194, preferably, may, on the other end of the tube 208 (as seenin FIG. 24), reversibly hold a medical device that is desired to beguided into or placed in a location in a body.

The torquer 198 may retain a guide wire, or lock the guide wire inplace, by radially compressing the guide wire within a lumen runningthrough the torquer 198. the torquer tip 204 is cooperatively threadedto the torquer body 200 (not shown), such that when the torquer tip 204is turned (e.g., clockwise) the torquer tip 204 moves closer to thetorquer body 200, which in turn causes the collet 202 (which is attachedto the torquer body 200) to be pushed into the tip 204 and compressed inthe tip 204 in an accordingly shaped orifice (not shown) in the tip 204.The collet 202 has any number of slots that allow the collet 200 to beradially compressed. The collet 202 is also preferably made of alubricious polymer (e.g., Delrin™, PEEK™, or certain grades of nylon),such that the collet 202 is able to move as necessary within the othercomponents of the torquer 198. Therefore, a guide wire running through alumen in the torquer 198, and collet 202, may be compressed and held inplace.

Preferably, the torquer 198 and the end 208 of the guide member 194 mayboth be sized and shaped to pass through a small thoracotomy incision(e.g., roughly 1 cm, and/or a 10 or 12 mm trocar port). The guide member194 may have a length sufficient to enter a superior thoracic incision,pass around one or more anatomic structures of the heart and then exitan inferior thoracic incision, whereby both ends of the guide may bevisible ex vivo or outside the patient's body (e.g., roughly 16″ to18″). The guide member 194 may have a smooth shape to allow its passagearound various anatomic structures while not causing substantial tissuedamage. The guide member 194 may have one or more portions that have adurometer range of about 40 to 90 shore A.

FIG. 28 illustrates (with arrows) how, in an exemplary embodiment of thepresent invention, rotating the control wheel 44 towards the proximalend 50 of the handle 14 curves or articulates the distal portion 16 ofthe shaft 12 of the dissector 10 into a curved configuration. As shownin FIG. 29, rotating control wheel 44 towards the distal end 36 of thehandle 14 returns the dissector 100 to its original configuration, i.e.,straightens out the distal portion 16. Although not shown in FIGS. 28,29, graphical indicators on the handle 14 may be included that correlateto the amount of curvature of the distal portion 16 based on the amountof control wheel 44 rotation.

For use in cardiac procedures, such as those treating arrhythmias of theheart as described above, the overall length of the dissector 10 maypreferably be roughly less than or equal to 70 cm. The useable shaft 12length including an articulating distal portion 16 at 0 degrees may beroughly less than or equal to 50 cm. The shaft 12 is preferably ofsuitable length to allow a surgeon to position the distal portion 16 ofthe dissector 10 behind and around anatomic structures of a beatingheart without unintended tissue damage. The handle 14 length may beroughly less than or equal to 30 cm. The handle 14 outer diameter, wherethe handle 14 is to be gripped by the operator, may be roughly be 2.5 to5 cm. The shaft 12 outer diameter may be roughly 0.250″ to 0.4375″. Thelength of the distal portion 16 having the ability to be articulated maybe about 5 cm to 15 cm. The range of motion of the articulating distalportion 16 may have a range of motion of about 0 to at least 180 degreesand, in one embodiment, not more than 180 degrees and, in anotherembodiment, between 0 and 165 degrees. The variable radius ofarticulation of the distal portion 16 may have a minimum radius of about2.5 cm, when articulated at about 165 degrees, thereby allowing properpositioning around certain anatomic structures, e.g., cardiacstructures.

The present invention also includes a method of using the dissector 10and the other components of the system, and a method of dissectingand/or guiding a medical device (e.g., ablation device) into a body. Oneexemplary method using minimally invasive techniques is described belowwith reference to FIGS. 30-36. However, other methods, using differentpoints of entry or an open surgical approach, for example, are alsocontemplated by the present invention.

FIG. 30 is an illustration of a chest cavity of a representative patientwith a view from the right side of the patient. FIG. 30 includes a viewof the heart 208, a thoracotomy 210 and first and second ports 212, 214,respectively. FIG. 30 also illustrates a first step in a procedure ormethod of using the dissector 10 of the present invention for anablation procedure, and pulmonary antrum isolation, in particular. Ascan be seen in FIG. 30, the distal tip 30 of the shaft 12 is firstinserted through a first port 212, or pericardial incision, thatprovides access to the heart. The first port 212 may be a roughly 1 cmincision or a 10 mm trocar port, for examples, although other sizes arealso contemplated. The distal portion 16 of the dissector 10 is in asubstantially straight configuration so that the distal portion 16 maypass easily through the port 212. The dissector 10 is then advanced intothe body so that the distal tip 30 is near the area of the pair ofpulmonary veins 216 on the right side of the heart and near thepericardial reflections (on the back side of the heart, and not seen inFig.) that generally need to be dissected to place an ablation deviceproperly in pulmonary antrum isolation procedures. The illuminationsource 32 of the dissector 10 may be illuminated to help confirm thelocation of the distal tip 30. The distal tip 30 may be used to create apassageway through the pericardial reflections by perforating thepericardial reflections with the tip 30.

FIG. 31 illustrates a next step in the method of using the dissector 10for pulmonary antrum isolation. Once the distal tip 30 is in the desiredlocation near the pulmonary veins 216, as shown, the control wheel 44 isrotated toward the proximal end 50 of the handle 12, which articulatesthe distal portion 16 of the shaft 12 of the dissector 10 around thepulmonary veins 216. The articulation lock 46 is then moved to a lockedposition (as indicated by the arrow) so that the distal portion 16 maystay in the desired articulated position around the pulmonary veins 216and will not straighten until desired.

FIG. 32 illustrates the next step in the method, which is to place aguide wire 218 in the opening 74 (shown by arrow) and extend the guidewire 218 through the guide wire tube 68 so that the distal end 220 ofthe guide wire 218 extends out (e.g., by approximately 1 cm) the distalend of the guide wire tube 68, or opening 72, in the distal tip 30, asshown. The guide wire 218 is then extended out through the thoracotomy210 where it is to be connected to a guide member 194 (not shown inFig.). Although the exemplary method involves extending the guide wire218 out through the thoracotomy 210, the guide wire 218 couldalternatively extend out of the body through a smaller opening or port.If so, it may be necessary to use a surgical forceps to reach into theopening or port and grab the distal end 220 of the guide wire 218 andpull it out through the port, where it could be attached to a guidemember 194.

Next, as illustrated in FIG. 33, the guide wire 218 is connected to aguide member 194. The connection between the guide wire 218 and theguide member 194 may be made by inserting the guide wire 218 in the endof the torquer 198 on the guide member 194. The torquer tip 204 may thenbe twisted, e.g., clockwise, to secure the guide wire 218 in place. Thenext step, as illustrated in FIG. 33, is to pull the guide wire 218 backout through the dissector 10 in the direction shown by the arrow, whichmoves the guide member 194 closer to the end of distal tip 30 of thedissector 10. The guide wire 218 is pulled until the torquer 198 of theguide member 194 comes substantially into contact with the distal tip 30of the dissector 10, as shown by FIG. 34. The next step, alsoillustrated in FIG. 34, is to lock the guide wire lock 48 by turning (asshown by arrow), e.g., clockwise, the guide wire lock 48.

FIG. 35 illustrates a next step in the method, which is to attach anablation device 222 to the end of the guide member 194 opposite thetorquer 198. In order to guide the ablation device 222 into the body tothe correct location, the next step in the method is to withdraw thedissector 10 (and guide wire 218) back out through the port of entry 212and thereby pull the ablation device 222 into place. In order to removethe dissector 10, the distal portion 16 generally needs to bestraightened first by unlocking the articulation lock 46 (as shown byarrow) and then by rotating the control wheel 44 toward the distal end36 of the handle 14 the dissector 10. The dissector 10 is then manuallywithdrawn from the first port 212. As a result, the attached guidemember 194 is pulled through the pericardial reflections and out throughthe port 212, thereby pulling the attached ablation device 222 to thearea of pulmonary veins 216. In order to place the ablation device 222around the pulmonary veins 216, as shown in FIG. 36, the jaws 224 of theablation device 222 are closed around the veins 216.

Any known or future developed ablation device is contemplated as beingused with the present invention. Such an ablation device may apply anytype of suitable energy, such as RF energy, HIFU energy, microwaveenergy, thermal energy, cryogenic energy, laser energy or ultrasoundenergy, for examples, to target tissue. A particular, preferred ablationdevice is a bipolar ablation device, although all types of ablationdevices are contemplated.

In other embodiments of the present invention, it is contemplated thatthe dissector 10 can include components for other purposes besidesdissection and guidance. For example, instead of using the dissector 10to place a separate ablation device, the means for performing ablation(e.g., ablating or energy transfer elements) may be included in thedissector 10. The means for performing ablation or energy transfer cancomprise any energy transfer elements that transfer energy to targettissue. For example, energy may be conductive elements that may supplyRF energy (as shown in Figs), HIFU energy, microwave energy, thermalenergy, cryogenic energy or ultrasound energy to target tissue. Energytransfer elements may be, for example, laser elements for supplyinglaser light to target tissue. Two or more energy transfer elements orconductive elements may be arranged in a bipolar arrangement wherein atleast one element is used as a positive electrode and at least oneelement is used as a negative electrode. One or more energy transferelements or conductive elements of the ablation device 12 may bearranged in a monopolar arrangement wherein at least one element is usedas one electrode and an indifferent electrode is placed elsewhere on thepatient's body such as the back, thigh or shoulder or another site otherthan the ablation device 12 site.

Energy transfer elements or conductive elements may comprise one or moreconductive materials or blends including titanium, titanium alloys, TiNialloys, shape memory alloys, super elastic alloys, aluminum oxide,platinum, platinum alloys, stainless steels, stainless steel alloys,MP35N, elgiloy, haynes 25, satellite, pyrolytic carbon, silver carbon,conductive metals, conductive polymers or plastics, and/or conductiveceramics. Energy transfer elements or conductive elements may not beconductive but may serve as a conduit to deliver a conductive materialsuch as a conductive fluid. Energy transfer or conductive elements maybe porous. For example, energy transfer elements or conductive elementsmay comprise porous polymers, metals, or ceramics. Energy transferelements or conductive elements may be coated with non-stick coatingssuch as PTFE or other types of coatings as discussed herein. Inparticular, the energy transfer elements may comprise one or morecoatings, e.g., hydrophilic coatings. Energy transfer elements orconductive elements may be flexible thereby allowing them to conform tothe surface of target tissue. Energy transfer elements or conductiveelements may be malleable thereby allowing a surgeon to shape them toconform to the surface of target tissue.

Energy transfer elements or conductive elements may comprise one or moremetal conductors such as windings inside a polymer or a conductive meshmaterial. The energy transfer elements or conductive elements maycomprise tubes for delivery of fluids. The tubes may comprise holes orslots. A polymer tube may be placed inside a metal tube to control fluiddelivery through energy transfer elements or conductive elements. One ormore of the energy transfer elements or conductive elements may be usedas one or more nerve stimulation electrodes and/or as one or morecardiac stimulation electrodes. Electrodes may be used for cardiacpacing, defibrillation, cardioversion, sensing, stimulation and/ormapping.

Energy transfer elements or conductive elements may comprise needlesdesigned to penetrate tissues such as fat and muscle. For example,energy transfer elements or conductive elements may be designed topenetrate fat on the heart thereby allowing the energy transfer elementsor conductive elements to reach cardiac tissue. The needles may allowfluids such as conductive fluids, chemicals such as ablation chemicals,drugs, biological agents and/or cells to pass through. The needles mayallow a vacuum or suction to pass through.

In addition, the dissector 10 may include components for other featuresbesides ablation. For example, the dissector 10 may include means fortracking the position of the device 10 in a body (e.g., tracking thedistal portion 16). An example of a disclosure of such a tracking meansis described in U.S. Patent Application Publication US 2006/0229594 A1(Francischelli et al.), and is herein incorporated by reference in itsentirety. Alternatively, or additionally, the dissector 10 may includeany other desired features. For example, the dissector 10 may includeany of the following features: sensing capabilities, imagingcapabilities, fluid transfer (e.g., hydration and/or desiccation)capabilities, aeration capabilities, and cutting capabilities (e.g.,cutting tool included on distal portion). Other suitable capabilitiesare also contemplated by the present invention.

The next step in such a method is that the guide member 194 is removedfrom the ablation device 222. The dissector 10 and guide member 194 arethen completely removed from the patient. Ablating energy is thendelivered to the ablation device 222 to ablate tissue. Following theablation procedure, the ablation device 222 is withdrawn or removed fromthe patient. In the exemplary method illustrated in FIGS. 30-36, thejaws 224 would be removed from the pulmonary veins 216, and the ablationdevice 222 would be withdrawn back through the thoracotomy 210 and outof the body.

Without reference to any particular figures, in general, the presentinvention contemplates using the dissector 10 as part of a system fordissecting tissue and/or guiding a medical device to a desiredphysiological location. The system may comprise: a dissecting/guidingdevice 10, comprising: an elongate shaft 12 comprising a proximalportion 18 and a distal portion 16, wherein the distal portion 16comprises a plurality of segments that articulate with respect to oneanother; a handle 14 attached to the proximal portion 18 of the shaft12, wherein the handle 14 comprises controls for articulating theplurality of segments of the distal portion 16 of the shaft 12 withrespect to one another; and a guide wire tube 68 through at least aportion of the length of the dissecting/guiding device 10, wherein theguide wire tube 68 comprises proximal and distal ends each having anopening; a guide wire that may be fed into the proximal end of the guidewire tube 68, through the guide wire tube 68 and out through the distalopening of the guide wire tube 68; and a guide member 194 comprising anelongate structure with two ends, wherein a first end may attach to adistal end of the guide wire and a second end that may attach to amedical device, such that when the guide wire, with the medical deviceattached, is retracted back through the guide wire tube 68, the medicaldevice is guided to a desired physiological location.

FIGS. 30-36, discussed above, demonstrate using the dissector 10 todissect pericardial reflection tissue and to place an ablation device totreat atrial fibrillation. However, the present invention alsocontemplates using the dissector 10 more broadly during other surgicalprocedures performed to treat other conditions. Therefore, more broadly,the present invention includes a method of surgical dissection of tissuewith a dissector 10 comprising: an elongate shaft 12 comprising aproximal portion 18 and a distal portion 16, wherein the distal portion16 comprises a plurality of segments that articulate with respect to oneanother and the plurality of segments includes a distal segment 20having a distal end; and a handle 14 attached to the proximal portion 18of the shaft 12, wherein the handle 14 comprises controls forarticulating the plurality of segments of the distal portion 16 of theshaft 12 with respect to one another, comprising the steps of:positioning the distal end of the dissector 10 in a body; advancing thedistal end through the body to dissect tissue; and simultaneouslyarticulating the plurality of segments with respect to one another. Thedistal end may include an illumination source 32, and the method mayfurther comprise the step of visually locating the distal portion 16 ofthe elongate shaft 12 by observing visible energy from the illuminationsource 32 passing through tissue, or may further comprise the step ofdifferentiating tissue by observing visible energy from the illuminationsource 32 through tissue.

The present invention also includes a method of guiding a second deviceto a desired physiological location with a first device comprising: anelongate shaft 12 comprising a proximal portion 18 and a distal portion16, wherein the distal portion 16 comprises a plurality of segments thatarticulate with respect to one another and the plurality of segmentsincludes a distal segment 20 having a distal end; a handle 14 attachedto the proximal portion 18 of the shaft 12, wherein the handle 14comprises controls for articulating the plurality of segments of thedistal portion 16 of the shaft 12 with respect to one another; and aguide wire tube 68 having a proximal and a distal end, wherein the guidewire tube 68 is disposed along at least a portion of the length of thefirst device and the guide wire tube 68 has openings at both theproximal and distal ends, comprising the steps of: inserting the firstdevice, distal end first, into a first opening in a body with theplurality of segments of the distal portion in a substantially straightconfiguration; advancing the distal end through the body; articulatingthe plurality of segments with respect to one another to position thedistal portion in a desired physiological location; feeding a guidewire, having a proximal and a distal end, into the proximal opening ofthe guide wire tube, distal end first, and through the guide wire tubeuntil the distal end of the guide wire comes out the distal opening ofthe guide wire tube in the distal end of the first device; connectingthe second device to the distal end of the guide wire; and pulling theguide wire back through the first device and thereby pulling the seconddevice adjacent the distal end of the first device at or near a desiredphysiological location. The method may further comprise the step ofremoving the first device through the first opening. Prior to the stepof removing the first device, the distal portion of the first device maybe returned to the substantially straight configuration. The method ofguiding may further comprise the steps of: disconnecting the seconddevice from the guide wire; and removing the first device and the guidewire through the first opening. The second device in the method may beinserted into the body through a second opening in order to connect thesecond device to the guide wire. If the distal end includes anillumination source 32, the method may further comprise the step ofvisually locating the distal end of the elongate shaft 12 by observingvisible energy from the illumination source 32 passing through tissue.The illumination source 32 may be turned off and on. If the first devicefurther comprises an articulation lock mechanism for maintaining thedistal portion 16 of the device in a desired articulated configuration,the method may further comprise the step of locking the distal portion16 in the articulated position while the distal portion 16 is in thedesired physiological location. Additionally, with the presence of anarticulation lock mechanism (i.e., control wheel lock), lock could beunlocked to allow the distal portion 16 of the first device to bereturned to the substantially straight configuration, particularly priorto removal from through the first opening. If the first device furthercomprises a guide wire lock that can maintain the position of the guidewire in the guide wire tube 68, the method may further comprise the stepof locking the guide wire in a position in the guide wire tube 68 afterthe step of pulling the guide wire back through the first device.

A method combining the steps of dissection and guiding of a seconddevice is also contemplated by the present invention.

The dissector 10 and its components, as well as the other parts of thesystem disclosed, are preferably made of biocompatible materials such asstainless steel, biocompatible epoxy or biocompatible plastic.Preferably, a biocompatible material prompts little allergenic responsefrom the patient's body and is resistant to corrosion from being placedwithin the patient's body. Furthermore the biocompatible materialpreferably does not cause any additional stress to the patient's body,for example, it does not scrape detrimentally against any element withinthe surgical cavity.

It will be appreciated by those skilled in the art that while theinvention has been described above in connection with particularembodiments and examples, the invention is not necessarily so limited,and that numerous other embodiments, examples, uses, modifications anddepartures from the embodiments, examples and uses are intended to beencompassed by the claims attached hereto. The entire disclosure of eachpatent and publication cited herein is incorporated by reference, as ifeach such patent or publication were individually incorporated byreference herein.

We claim:
 1. A surgical dissector comprising: an elongate shaftincluding a proximal portion and a distal portion, wherein the distalportion comprises a plurality of hingedly interconnected segments thatarticulate with respect to one another and the plurality of segmentsincludes a distal segment having a distal end; and a handle attached tothe proximal portion of the shaft, wherein the handle comprises controlsfor articulating the plurality of segments of the distal portion of theshaft with respect to one another; wherein each of the plurality ofsegments are hingedly interconnected with a respective pin that extendslaterally through adjacent segments; and a push/pull rod interconnectedto a plurality of connected pistons serially and hingedly interconnectedadjacent the plurality of segments; wherein the entirety of thepush/pull rod is positioned proximal the plurality of pistons and theplurality of pistons are positioned distal to the push/pull rod.
 2. Thesurgical dissector of claim 1, wherein the distal end includes anillumination source.
 3. The surgical dissector of claim 1, wherein theplurality of pistons are serially and hingedly interconnected with aplurality of links.
 4. The surgical dissector of claim 3, wherein eachlink includes two holes in which respective pins are received.
 5. Thesurgical dissector of claim 1, wherein, in a straight configuration, theplurality of segments and the plurality of pistons are parallel andadjacent with respect to each other.
 6. The surgical dissector of claim1, wherein a proximal end of the push/pull rod is pivotally connected tothe distal segment.
 7. The surgical dissector of claim 1, furthercomprising a flexible guide wire tube extending lengthwise along theelongate shaft.
 8. The surgical dissector of claim 7, wherein the guidewire tube extends adjacent an illumination source.
 9. The surgicaldissector of claim 1, further comprising a handle that controls movementof the push/pull rod.
 10. The surgical dissector of claim 9, furthercomprising a rack extending from the push/pull rod, the rack including aset of teeth.
 11. The surgical dissector of claim 10, wherein the handleincludes a set of teeth that engage the set of teeth of the rack. 12.The surgical dissector of claim 11, further comprising a jam barconnected to the rack.
 13. The surgical dissector of claim 12, furthercomprising a guide wire tube supporting a jam plate having an aperturealigned with the jam bar.
 14. The surgical dissector of claim 1, furthercomprising an articulation lock mechanism for maintaining the distalportion of shaft in a desired articulated configuration.